[Clinical features, diagnostics and treatment of FGF23 secreting tumors: series of 40 clinical cases]

INTRODUCTION

Tumor-induced osteomalacia is an acquired rare disease manifested by hypophosphatemic osteomalacia due to excessive secretion of fibroblast growth factor 23 (FGF23). FGF 23 is a non-classical hormone secreted by bone tissue (osteocytes) and regulates phosphorus metabolism.The aim of this work is to present clinical experience in the diagnosis, treatment and rehabilitation of patients with tumor-induced osteomalacia.

MATERIALS AND METHODS

40 patients with clinically-confirmed tumor-induced osteomalacia were included in the study, 34 of whom had the tumor localized, 27 underwent surgical treatment and 21 achieved stable remission.

RESULTS

The median age was 48 [41; 63] years, 43% were men, the time left from the the onset of the disease was 8 [4; 10] years. Biochemical findings were hypophosphatemia 0.47 [0.4; 0.53] mmol/l, a decrease in the tubular reabsorption phosphate 62 [52; 67]%, and an increase in alkaline phosphatase of 183 [112; 294] units/l. At the time of diagnosis, 100% had multiple pathological fractures, only 10% could move independently, and 77.5% classified the pain as unbearable (8-10 points according to the 10-point pain syndrome scale ). Among the methods used to detect tumors, the most sensitive were scintigraphy with tectrotide with SPECT/CT 71.4% (20/28) and MRI 90% (18/20). In 35% of cases, the tumor was localized in soft tissues and in 65% in bone tissue; The tumor was most often detected in the lower extremities, followed by the head in frequency of localization. 18 patients currently have no remission and they receive conservative treatment (phosphorus and alfacalcidol n=15 and burosumab n=3). In case of achieving remission (n=21), regression of clinical symptoms and restoration of bone and muscle mass was observed. Extensive excision of the tumor without prior biopsy resulted in the best percentage of remission - 87%.

CONCLUSION

Tumor-induced osteomalacia is characterized by severe damage to bone and muscle tissue with the development of multiple fractures, muscle weakness and severe pain syndrome. In laboratory diagnostics, attention should be paid to hypophosphatemia, a decrease in the tubular reabsorption phosphate index and increased alkaline phosphatase. The use of functional diagnostic methods with a labeled somatostatin analogue to the subtype 2 receptor and MRI with contrast enhancement are the most accurate methods of topical diagnostics. In case of localization of the tumor, a wide excision without a preliminary biopsy is recommended.

[Effect of bone anabolic therapy on bone remodeling and bone density in geriatric patients with osteoporosis and falling syndrome]

BACKGROUND

Older adults with severe osteoporosis are the most vulnerable group of geriatric patients. They are shown the purpose of anti-osteoporotic therapy, which should be effective and safe. Teriparatide showed a decrease in the risk of fractures, an increase in BMD. In Russia, the use of teriparatide in the geriatric population is extremely scarce.

AIM

assess clinical course, bone metabolism parameters and efficacy of bone-anabolic therapy in elderly and senile patients with severe osteoporosis and falls.

MATERIALS AND METHODS

The longitudinal prospective study included 100 patients 60 years and older with severe osteoporosis who had one or more falls within the last year. All patients were prescribed calcium and vitamin D preparations and bone-anabolic therapy (teriparatide 20 mg daily subcutaneously). The duration of follow-up was 24 months and included 3 visits: screening, at 12 and 24 months. The effectiveness of bone-anabolic therapy was carried out on the basis of assessing the frequency of new fractures, reduction of pain, changes in BMD according to X-ray densitometry, dynamics of bone metabolism markers.

RESULTS

All patients had severe osteoporosis and aggravated comorbidity status, suffered a fall within the last year, and also low-energy fractures in the past. One in three patients had a vertebral fracture, one in five had a proximal femoral fracture. Prior to the start of the study, 61 patients received antiosteoporotic therapy. During the follow-up, 4 patients died, 96 patients completed the study. Against the background of teriparatide therapy, a decrease in the number of new cases of low-energy fractures and the number of patients with chronic pain was obtained. An increase in BMD was noted in the lumbar spine after 24 months and in the femoral neck after 12 months. There was no negative dynamics of the BMD. Also after 12 months, an increase in P1NP and C-terminal telopeptide of collagen type 1 was noted, after 24 months - osteocalcin and C-terminal telopeptide.

CONCLUSION

The use of teriparatide can be recommended as an effective intervention to treat severe osteoporosis in geriatric patients with falls.

[The clinical practice guidelines for primary hyperparathyroidism, short version]

Primary hyperparathyroidism (PHPT) is an endocrine disorder of parathyroid glands characterized by excessive secretion of parathyroid hormone (PTH) with an upper normal or elevated blood calcium level. Classical PHPT refers to a symptomatic, multi-system disorder, wich can lead to a significant decrease in the quality of life, disability of patients, and even an increased risk of premature death. Hypercalcemia and the catabolic effect of PTH on various cells are considered as the main pathogenetic mechanisms of the PHPT associated complications. In the last two decades, there has been an increase in the incidence of PHPT, mainly due to the mild forms of the disease, primarily due to the routine calcium screening in North America, Western Europe and, Asia. High prevalence of the disease, as well as the variety of clinical manifestations, cause the attention of different specialists - physicians, rheumatologists, urologists, nephrologists, cardiologists and other doctors. This review cover the main issues of Russian guidelines for the management of PHPT, approved in 2020, including laboratory and instrumental methods, differential diagnosis, surgical and conservative approach, short-term and long-term follow-up. This guidelines also include the recommendations for special groups of patients with hereditary forms of PHPT, parathyroid carcinoma, PHPT during pregnancy.

[Characteristics of geriatric and somatic status in patients with osteoporosis]

BACKGROUND

Older adults with osteoporosis (OP) and high risk of falls are the most vulnerable group of patients with respect to the development of fractures. Falls and fractures in elderly patients with OP are associated with geriatric syndromes and worse functional status.

AIM

To аssess comorbidity and geriatric status in elderly and senile patients with and without OP.

MATERIALS AND METHODS

The study included 607 patients over 60 years of age hospitalized in the geriatric department. According to the presence of OP, the patients were divided into 2 groups: group 1 - patients with OP (n=178, 29.3%), group 2 - patients without OP (n=429, 70.7%). All patients underwent a general clinical study, an assessment of comorbidity -according to the Charlson index, and a comprehensive geriatric score.

RESULTS

OPs had 178 (29.3%) patients, more often these were women. 55.6% of patients with OP were disabled. Age--related diseases such as Alzheimer's disease, Parkinson's disease, osteoarthritis, anemia, thyroid disease, varicose veins were significantly more common in patients with OP. With almost all of these diseases, a univariate analysis revealed an association with OP. Geriatric syndromes such as frailty, hypodynamia, malnutrition, polypharmacy, urinary incontinence were significantly more common in group 1 patients. Patients with OP were more likely to live alone and use mobility aids compared to patients without OP.The univariate analysis demonstrated that OP is associated (OR 1.54 to 2.00) with frailty, hypodynamia, the use of aids in movement, sleep disorders, sensory vision deficiency, urinary incontinence. The Functional status of patients with OP was worse compared to patients without OP. Patients with OP suffered more fractures, and vertebral fractures were significantly more frequent.

CONCLUSION

Patients with OP have a high comorbidity, a burdened geriatric status. In elderly patients, it is necessary not only to screen and diagnose OP, to assess the risk of 10-years probability of major pathological fractures using the FRAX algorithm, but also to conduct a comprehensive geriatric assessment to diagnose geriatric syndromes that weaken the course of OP and lead to more serious consequences.